I. noun suffix Etymology: perhaps from 1oh one that is, has the qualities of, or is associated with , II. interjection suffix Etymology: probably from 1oh — in interjections formed from other parts of speech
-O
Meaning of -O in English
Merriam Webster. Explanatory English dictionary Merriam Webster. Толковый словарь английского языка Мерриам-Уэбстер. 2012